The overall goal of this project is to develop a computerized self- monitoring system (CSMS) for use in clinical and research settings. The product will be a toolkit that will allow behavioral scientists with no programming experience to develop and implement a broad range of customized self-monitoring protocols. The toolkit will consist of a front- end software program (FESP), a hand-held computer (HHC), and hardware for exchanging information between the hand-held computer and any other PC. The FESP will be used to develop the assessment protocols, which will then be downloaded to and implemented via the HHC. The HHC will be carried by research subjects or therapy patients and used as an interactive self- monitoring tool. A primary feature of the product will be the capability to rapidly upload data from the HHC to the FESP. The Phase l project will emphasize development and testing of a prototype CSMS. During Phase Il, a more complete CSMS will be developed, and broad-based testing of the product will be conducted in a variety of clinical and research contexts.